Mobile unit and track system therefor



Nov. 24, 1959 c. w. WOLF 2,913,997

MOBILE UNIT AND'QTRACK SYST M THEREFOR Q 13 Sheets-Sheet 1 Filed July 30. 1958 INVENTOR.

Carl W. Wolf ATTORNEY United States Patent MOBILE UNIT AND TRACK SYSTEM. THEREFOR Carl W; Wolf, York, Pa.

Application July 30, 1958, SrialNo. 751,960

15 Claims. (Cl. 104-148) This application is a continuation-in-part of my application Serial No. 524,777, filed July 27, 1955.

This invention relates to a mobile. unit and'a track system for supporting and guiding said unit during movement thereof. More particularly, the mobile unit and track system are preferably of miniature size andutilize a.

mono-rail principle or spaced rails, in either event however, the tracks preferably are capable ofbeing-twisted.

spirally in an axial direction, as well as. being. curved,

about radii within the plane of the track and transverse,

thereto. The range of sizes employedin toy sizes, of electric trains is well suited for adaptation, to the present invention although the invention. also lends itself, to use in somewhatlarger sizes-than are commonly employed in toy trains if desired, especially for advertising or utilitarian purposes.

The invention is well adapted-for a variety of uses including toy constructions;advertising displays; and industrial or commercial systems such as money conveyors in stores, carrying parts from one location to another in factories, stores and the like, as well as for the transporting of dangerous material such as radio-active substances, all of which uses may embody principles of remote control for the mobile unit.

One of the principal advantages of the present invention is that the means for supporting the mobile unit upon a track areso designed that much more rapid speeds may be employed than is possible now in toy trains for example, without the danger of the mobile unitbecoming the track system. The shape'of the. rollers which co operate with several types of unique designs of trackwhich are engaged by said rollers contribute to this re sult. Accordingly, the unit may climb or descend vertically, or run upright, sidewise, or inverted upon the track. Also, the mobile unit adjusts itself from narrow economical track to wider, more stable track when conditions require the same.

Other advantageous features of the invention comprise the employment of a relatively few basic elements which are used in multiples and are readily interchangeable so as to minimize inventory stock; simplicity of design so as to maintain manufacturing costs at aminimum; ruggedness in construction and design features which minimize wear of the individual components; and the utilization ofv has been installed and an exemplary mobile unit in the form of a toy is mounted upon said track.

Fig. 2 is a plan view of one embodiment of an ex- 2,913,997 Patented Nov. 24,, 1959 a section of one embodiment of track, all embodying the present principles of the invention. I

' Fig. 4 is a transverse sectional view of the mobile unit shown in Fig. 3. and taken on the line 4-4 of Fig. 3.

Fig. 5 is a view similar to Fig. 4 butshowing a, wider form of said embodiment of track utilized to support the mobile unit.

Fig. 6'is a side view of an exemplary combination of two mobile units connected together by means comprising part of the present invention.

Fig. 7 is a fragmentary sectional view taken transversely through another embodiment of track member which may be used to support said one, embodiment of mobile unit illustrated, in the foregoing figures in accordance with the principles of the invention and also afford additional current conductors.

Fig. 8 is an exploded top plan view of a pair of the supporting members. shown in Figs. 3-5 in. position to be assembled together for relative pivotal movement.

Fig. 8a is an end elevation of one of the supporting members shown in Fig. 8.

Fig. 9 is a perspective view of a mobile unit having another arrangement of rollers engaging another embodiment of track.

Fig.10 is a longitudinal view of the mobileunit'shown in Fig. 9, partly in vertical section to illustrate details of the mounting of the roller supporting means and drive, means for the rollers, on a larger, scale than in Fig. 9.

Fig. 11 is a transverse sectional view of the mobile unit taken on the line 11 -11 of Fig. 10 and shown with the rollers engaging the embodiment of track shown in Fig. 9.

Fig. 12is a view similar. to Fig. 11 but showing the rollers moved together to effect disengagement of the mobile unit from the track.

Fig. 13 is a perspective view of a spring element detail used to urge the rollers of the mobile unit into engage ment with the track rails.

Fig. 14 is an end view of. the exemplary rail shown in,

in the drawings is exemplary only and primarily is illus trated for purposes of affording means for containing or providing a support for the operating mechanism and the means by which the unit is supported upon a track embodying the principles ofthe invention; For example, in Fig. 1, the mobile unit 10 is illustrated as a rocket-like toy capable of traveling at relatively high speeds, if desired, along an exemplary track system 12 which may be affixed to the walls, ceiling, and floor of a room by any suitable means such as suction cups 14, as illustrated in Fig. 4, or screws or nails 22 as shown in Fig. 5. However, the mobile unit may be used' for utilitarian purposes such as in advertising displays, transporting objects. in commercial or industrial establishments, as well as for many other useful purposes.

The embodiment of track 12 is a mono-rail type that is approximately T-shaped in cross-section as is obvious from Figs. 4, 5 and 7, but such cross-sectional shape is not to be regarded as restrictive. Where for example the mobile unit is energized by an electric motor, to be configuration as illustrated in Fig. 1. The preferred cross-sectional shape of the track 12 includes continuous electrical conduits such as copper wires 18 which are afiixed to opposite edges of the head of the T-shaped supporting base member 16 such as by bonding of the metal to the resin or other insulating material. Mechanical anchorages such as the dove-tail flanges 20 which are formed integrally on the wires 18 as shown in Fig. 7, may be employed to further facilitate uniting of the wires to the supporting base member 16, if desired. The formation of the track may be accomplished by a suitable extrusion molding process. Hence the production costs thereof are reasonable. The width of the head of the track such as the distance between the conduits 18 may be varied in accordance with the stability desired for the mobile units to run thereon. The wider the head, the greater the stability.

The T-shaped cross-sectional formation of the track 12 renders it relatively rigid, particularly when formed from suitable resinous material and especially as reinforced by the wires 18, whereby only occasional attaching means such as screws or nails 22, as shown in Fig. 5 relative to track 12, or suction cups 14 as shown in Fig. 4 relative to track 12, are necessary to secure the track to a supporting surface such as a wall or ceiling 24. Supporting base member 16 may be constructed of interrupted lengths such as railway ties when electrical conduits 18 are substantially strong enough to maintain position while the mobile unit is operating along the unsupported space between the sections of base member power control means 26, such as a conventional rheostat, is connected to the opposite wires 18 of the track, as well as to a source of current, not shown, by conventional lead wires 28. Preferably, as shown in Fig. 2, the wires 18 are not joined at their ends in a track system but the ends of each conductor are slightly spaced apart so as to be interrupted and the positive and negative connecting wires 30 from the control box 26 respectively are connected to opposite ends of the wires 18 of the track.

Switch means also may be employed in the exemplary track system as illustrated in Fig. 2. The switches 32 have relatively fixed bases including either remotely or directly controlled transversely slidable members 34, each of the slidable members having different suitably shaped track sections 36 and 38. Spring pressed detents 40 or other means may be used to hold the slides of the switches in any desired position of a predetermined number of different positions so as to effect desired connections of the track and routing of the mobile units relative to the switches and track. The ends of the wires 18 in the track members 12 which are afiixed to the switches, as well as the ends of the wires of the track sections on the switch slides 34, are arranged to make suitable contact with each other in any desired position of the slides 34 relative to the switch bases 32. Any convenient means may be used to insure positive electrical contact between the ends of the wires 18 but when the switch slides 34 are between operative positions, the circuit in all track sections is interrupted and movement of units is not possible. In view of this arrangement of track switches, and current supply which may use either DC or A.C., with two conductors, the current only can be directed through a closed track configuration, whereby the unit cannot run off the end of a section of open track.

Referring now to the exemplary mobile unit 10, the base member 42 may for example be cup-shaped as shown in Figs. 3 through 5 but it will be understood that any desired shape or ornamental arrangement of base member, either with or without an additional body, whether toy-like, fanciful, or utilitarian, may be attached to or substituted for the illustrated base member 42. Preferably, the base member is molded from suitable insulating material, such as artificial resin, for purposes to be described.

Supported within the base member 42 in longitudinally spaced relationship to each other are pairs of supporting members 44 which, for example, may be castings or stampings formed from suitable metal such as bronze, aluminum or otherwise, whereby they may be elongated, as shown in Figs. 3 through 5 and 8 to furnish bearing apertures 46 which support preferably metallic rotatable shafts 48. However, members 44 may be formed in other ways if desired such as from formed stampings having inserted bearings. The supporting members 44 also may be otherwise shaped but preferably are provided with interfitting ears 50. As will be seen particularly from Fig. 8, the ears 50 are so arranged on the members 44 that two identical members 44 may be interfitted as shown in said figure to constitute a pair of relatively pivotally movable members, the ears 50 also having disposed therebetween driving worms 52 which are fixed by pins 54 to drive shafts 56 extending in opposite directions from and connected to the opposite ends of drive shaft 58 of electric motor 60. Further, one car 50 of each member 44 is provided with a laterally extending sleeve 61 which fits rotatably in a bearing 61' aperture in the adjacent ear of the other member 44, whereby axial alignment of members 44 is assured independently of shafts 56, thus affording good gear and worm contact even though shafts 56 may be worn. Suitable insulating couplings 62 are used preferably to connect the ends of the motor drive shaft 58 to the drive shafts 56 in order to insulate the shafts electrically to control the circuit between the wires 18 of the tracks and the motor 60 as will be explained hereinafter.

Fixed to the outer ends of shaft 48, and preferably integral therewith, are similar rollers 64, one of which in each pair is metallic. The other is formed from suitable insulating material such as synthetic resin and particularly a phenolformaldehyde condensation product. The metallic roller 64 contacts one of the wires 18 of the track, while the opposite metallic roller 64 of the other pair on the opposite side of the motor 60 contacts the opposite wire l8 of'the track. The insulated rollers 64 may be fastened to the shafts 48 by any suitable means such as longitudinal fiutings, rivets, or otherwise, not shown. To facilitate the engagement of all of the rollers 64 with the opposite flanges comprising the edges of the head of the T-shaped track 12, each of the rollers 64 is provided with a preferably deep circumferential groove 66 which receive said track wires and flanges. Further, the rollers on one or both sides of the rail may be serrated and the track may be made with matching serrations, if desired to afford adequate frictional engagement.

Fixed to the opposite ends of shafts 48 from the rollers 64 are worm gears 68 which mesh with the worms 52 mounted in the units comprising the individual pairs of supporting members 44. Hence, rotation of the motor shaft 58 simultaneously will drive all four rollers 64 in unison and the rollers of each pair in opposite directions to drive the mobile unit 10 in either direction desired, motor 60 preferably being of the reversible type. Fur ther, if desired, matching helical gears may be substituted for driving worms 52 and worm gears 68 for higher rates a of peripheral speeds of rollers 66 relative to the speed of motor 60.

In view of the construction of the supporting members 44 set forth above, it will be seen that the ears 50 thereof provide pivotally movable means having axes coaxial with drive shaft 56, whereby the ends of the supporting members carrying the rollers 64 are pivotally movable toward and away from each other to move rollers 64 into and out'of engagement with the opposite edges of the flanges of track 12, as well as the exposed wires 18 on the outer edges of said flanges. Primarily for purposes of urging the roller ends. of the supporting members 44 toward. each other and the track member, when. the mobile unit is positioned thereon, each pair of supporting members 44 is provided with a pair of preferably leaf springs 70, said springs being secured by rivets or other-. wise at their opposite ends to any suitable location on the base member 42 such as the bottom as viewed in Figs. 3 through 5, the springs 7t) in Fig. 3 broken away to illustrate details of the driving mechanism.

The leaf springs 70 preferably are of suitable metal and the upper ends thereof slidably engage the exterior surfaces of supporting members 44, thus providing a centralizing effect upon base member 42 relative to the track. The strength of springs 70'also is such as-to insure firm engagement of the circumferential grooves 66 of the rollers 64 with the extremities of the flanges of the track 12 and wires 18, even when the mobile unit is traveling at relatively high speeds upon the track 12, turning sharp corners and otherwise, as well as compensating for any irregularities in the track. The shape of the track 12 as well as the depth of the grooves 66 in the wheels 64 are such as to permit a reasonable range of track widths yet insure such above described function even at said relatively high speeds, as well as provide adequate friction to permit even vertical climbing of unit 10. However, when it is desired to disengage the mobile unit from the track, the effect of the springs 70 may be readilyovercome manually to effect separation of rollers64 from the track. Spreading of the supporting members 44 to eifect connection of the unit '10 to the track likewise is readily achieved manually.

Inasmuch as one of each pair ofthe rollers 64, is of insulating material, and, in the exemplary illustration shown in Figs. 3 through 5, the base member 42 of mobile unit 10 also is formed from insulating material, the metallic springs 70 will make electrical contact with the metallie supporting members 44 as well as the single metallic wheel. 64 of each pair of wheels, said metallic wheel of each pair likewise making electrical contact with one of the conducting wires 18 of the track. Hence, the end of either one of the springs 70 which is secured to base member 42 may conveniently be used as a connection point-for a suitable wire or other conductor to the binding posts or other connecting means conventionally provided on the motor 60 according to the exemplary circuit shown in Fig. 2.

As explained above, opposite wheels in the two pairs used in each mobile unit are metallic and thereby respectivelyengage the opposite conductors 18 of the track 12. The insulated coupling member 62 between the motor shaft 58 and drive shafts 56 will prevent the conduction of electricity from the supporting member units, gears, etc. to motor 60. If desired, however, spring means such as simple helical springs may extend between members 44 of each pair to assist springs 70 in urgingthem toward each other. The couplings 62 also provide supporting means for one end of each of the drive shafts 56 in the exemplary construction illustrated herein, and the opposite ends of the drive shafts 56 are supported byfixed bearings 72 respectively formed in opposite ends of base member 42 as shown in Fig. 3.

In Fig. 6, a plurality of mobile units 10 are illustrated, these being coupled together by exemplary coupling means 74, the details of which include universal joints 76, one of which is connected to the outer end of one of the drive shafts 56 of the mobile unit shown on the left of Fig. 6, said unit including the motor 6%. However, it is contemplated that the right-hand mobile unit 10 as shown in Fig. 6 shall have no motor 60 inasmuch as it' is highly possible to provide a single motor 60 capable of driving a limited number of mobile units 10 by the utilization of coupling means 74 as shown in Fig. 6. Under the circumstances, the additional mobile units 10 are each provided with a single drive shaft 78 to which worms 52' or helical gears for operating the pairs of rollers may be attached, said worms or helical gears. not

beingJShOwn in: Fig. 6 for purposes ofv simplifying the illustrationbut will function as. shown in Fig. 3. 1

The end drive shaft 78 adjacent coupling 74 inFig. 6 is connected to the right-hand universal joint 76. Under. the circumstances, coupling 74, in the exemplary form illustrated herein, comprises a sleeve 80 in which one end of each of the universal joints 76 is slidably received, said ends being provided with slots 82, for example, and pins 84 extendthrough the sleeve 80 and the slots 82. Further, the ends of the universal joints 76 which extend into sleeve 80, as well as said sleeves, in cross-section, are formed of suitable complementary geometric shapes so as to prevent relative rotation between the members. However, longitudinal sliding may take place between the adjacent ends of universal joints 76 and sleeve 80.

due to the slots 82. Thus, when the connected mobile units 10 are moving around either an outside or an inside curve, the lengthening or shortening of the normal distance between said units may be compensated for by the slippage permitted by the coupling means 74 described above, while rotational driving movement continues. Especially on. light units having correspondingly smallerpower requirements, universal joints 76 and sleeve 80. may be replaced by a simple open helical spring attached to the drive and driving units to connect the same and serve as a flexible shaft.

In the event for example the weight of an object or articles to be conveyed by the units 10 is such that considerable frictional engagement between the grooves 66 of the rollers 64 and the track 12 is required, such as where the units may be moving vertically for example, it will be seen that the provision of a plurality of mobile units 10 in tandem, as illustrated in Fig. 6 will be advantageous to provide such extra frictional engagement and therein preferably at the same time the wire conductors- 18 are fabricated with the base member 16 such as by extrusion molding. At regular intervals or otherwise along the track 12, transverse openings 88 may be formed in the base member 16 of the track, extending into conductors 86, for the reception of insertable plug members 90. Access to auxiliary wires may be gained at positions intermittent to openings 88 by removing insulation. It will be understood of course that the auxiliary conductors 86 may be connected to any suitable source of electric current. and, by the engagement of the plug members 90 with said conductors 86, auxiliary equipment of any required or desirable nature may be furnished with power through lead wires 92 connected to the plugs 90.

Figs. 9 through 13 show another embodiment of the invention in which is illustrated a different arrangement of track, and engagement thereof by the rollers of the mobile unit, from that shown in the preceding figures. In this latter embodiment, the same basic principles as in the previous embodiment are utilized, namely, that the mobile unit is provided with two pairs of supporting and driving rollers, all of which are positively driven and the rollers of each pair respectively are equally and oppositely movable relative to each other by yieldable means so as to engage the track which, in this second embodiment, comprises a pair of spaced rails. However, the supporting members for the rollers and driving shafts therefor, in regard to each pair of rollers, are yieldably urged away from each other so that the rollers at all times firmly engage the rails to support the mobile unit upon the track and afford driving traction between the rollers and the track rails. The yieldable urging or biasing of the rollers into engagement with the track members also permits-the rollers to adapt themselves to any irregularlties in the track, as well as facilitate removal of the mobile unit from the track and engagement thereof with the track.

The essential features of this additional embodiment are shown in an overall manner in Fig. 9, wherein the mobile unit 94 has two pairs of grooved rollers 96 respectively disposed adjacent opposite ends of the unit. One roller of each pair is formed from insulating material such as synthetic resin or fiber, while the other roller of each pair is metallic and may be formed of suitable current conducting material such as brass, bronze, or the like. One roller of each pair respectively engages one of a pair of similar rails 98 which comprise a track for the unit 94.

The similar rails 98 each preferably comprise a cylindrical edge portion 100 which is engaged by the rollers 96, and the opposite edge is another preferably cylindrical portion 102 which anchors the rails to the supports or ties 104. The rails 98 may conveniently be formed from strip sheet metal such as hard aluminum, the same being rolled and shaped to form rails having a crosssectional or end shape as shown in Fig. 14. The web of track 98 is of less thickness than edge 102 which is preferably cylindrical in shape but is not so restricted. This construction affords adequate anchoring of the rails to the ties.

As best shown in Figs. 11 and 12, the ties 104 may be formed from suitable insulating material such as molded synthetic resin or fiber, preferably being somewhat yieldable so that slots 106 may be formed within projections 108 of the rails, which slots are complementary to the edges of the rails having the cylindrical portions 102 thereon, whereby the said edges of the rails may be snapped into the slots 106 of the projections 108 and be securely supported by said ties 104. The ties also may be formed with any suitable securing means such as holes 110 to receive nails, screws, or other afiixing means by which the ties 104 may be secured to a suitable supporting surface such as a sheet of plywood, wall, ceiling, floor, or otherwise. The ties 104 may be placed at suitable intervals and the central web portion of the rails between the cylindrical portions 100 and 102 is adequate to render the rails rigid so as to resist the engaging movement of the rollers 96 therewith. Further, this form of rail 98 lends itself readily to being coiled upon spools of reasonable diameter so as to facilitate the packing of the rail, especially in coil form, together with the mobile unit and power control means such as a transformer and switch, whereby all of these elements might be sold in an attractive box or package.

The mobile unit 94 preferably is formed from suitable insulating material such as molded synthetic resin and said unit comprises two somewhat similar halves 112 and 114 which meet along a median line 116. The separability of the halves 112 and 114 facilitates the mounting of the motor 118 and the supporting means for the rollers 96 therein and the making of the unit 94 in two half sections also facilitates the molding thereof.

The half 114 of the unit 94 may be considered the base member of the unit and each of the halves 112 and 114 respectively are internally provided with pairs of cooperating transverse webs 120 and 122 respectively adjacent the opposite ends of the unit 94, as well as pairs of intermediate cooperating transverse webs 124 and 126. Disposed between the spaced opposing surfaces of the webs 120 and 122, as well as between the spaced opposing surfaces of webs 124 and 126 are transverse bearing blocks 128 and 130, for purposes to be described. Suitable pairs of transversely spaced securing means, such as bolts 132, extend from the lower surface of half 114 of unit 94. as viewed in Fig. 10, upwardly through the S webs 122 and 126, through the bearing blocks 128 and 130, and into the opposing webs and 124, as clearly shown in Fig. 10 so as to secure the halves of the unit 94 together, as well as firmly fix the bearing blocks 128 and 130 in operative position. Bearing blocks 128 and 130 may be formed of suitable metal unless the halves 112 and 114 of the housing are formed of metal, in which event, blocks 128 and 130 then would be formed of insulating material such as self-lubricating resin.

The power means for the unit 94 preferably comprises the electric motor 118 which is of small size and capacity when the unit 94 is to comprise a small toy for example. In any event, the size of the motor 118 is commensurate with the size of the unit 94 and the power to be delivered thereby is selected so as to afford the unit 94 with ample power to propel the unit and any expected load thereon along the track by which it is supported. Suitable securing means such as bolts, not shown, extend between end portions of the motor frame 134 and the intermediate bearing blocks 130, thereby anchoring the motor 118 stationarily within the unit 94. The motor 118 is provided with an elongated drive shaft 136 which projects from opposite ends of the motor and the outer ends of the shaft respectively are connected to socketed ends 138 of gear shafts 140 which preferably are formed from rigid insulating material such as suitable synthetic resin. Appropriate interlocking means such as transverse pins, splines or press fitting, as shown, are provided between the ends of drive shaft 136 and the gear shafts 140 so that the same all rotate unitarily when the motor 118 is furnished with current by control means similar to that shown in the embodiment illustrated in Figs. 1 through 8, and particularly as shown in Figs. 1 and 2, comprising power control means 126 are illustrated.

The rollers 96 in the embodiment shown in Figs. 9 through 14 respectively are supported by shafts 142 rotatably mounted within the bearing sleeves of supporting members 144. The rollers 96 are fixedly secured to the outer ends of shafts 142 and to the inner ends of said shafts suitable worm gears 146 are fixed, as best shown in Figs. 11 and 12. The shafts 142, supporting members 144, and worm gears 146 all may be formed of metal, although to facilitate the manufacturing thereof, the worm gears 146 may be molded from synthetic resin if desired. A worm 148 is fixed to each of the gear shafts 140 and is disposed between each pair of worm gears 146 as clearly shown in Figs. 11 and 12, whereby the rollers 96 of each pair will be rotated respectively in opposite directions so as to afford a uniform direction of drive to the unit 94 relative to the track comprising rails 98.

The supporting members 144 of the embodiment shown in Figs. 9 through 14 are similar in design and function to the supporting members 44 of the embodiment shown in Figs. 1 through 8. particularly for further details of said supporting members not illustrated in Figs. 9 through 14. The supporting members 144 have interfitting ears 150 similar to the interfitting ears 50 of the members 44 shown in Fig. 8 and the interfitting ears 150 have bearing apertures to receive the gear shafts 140 to support the interfitting ears 150. The outer ends of the gear shafts 140 respectively extend through a suitable bearing aperture in the outermost bearing blocks 128, as shown in Fig. 10. The shoulders of the enlarged portions of socket ends 138 of gear shafts 140 serve to position one end of the pairs of interfitted supporting members 144 relative to shafts 140, in an axial direction, and the transverse bearing blocks 128 serve to position the pairs of interfitting supporting members 144 in the opposite direction upon gear shaft 140, thereby affording relatively simple supporting means for the pairs of members 144 adjacent opposite ends of the unit 94.

Movement of the pairs of interfitting supporting members 144 relative to the gear shafts 140, by which they are supported, is controlled by yieldable means, preferably Attention is directed to'Fig. 8

a spring 152, foreach pair of members 144, best shown in Fig. 13. Each spring has an intermediate, upstanding bight 154 which extends over an axially extending strut 156 shown in Figs. through 12 to position the springs 152 relative to the lower half 114 of unit 94. The struts 156 extend intermediately of openings 158 formed respectively in each end portion of the unit 94, one of said openings being shown in Figs. 11 and 12. The elongated bearings of supporting members 144 and the shafts supported thereby extend through the openings 158, one pair of such bearings extending through each opening and the struts 156 extend longitudinally of each opening 158.

The outer ends 160 of the spring 152 are bent outwardly, away from each other, and respectively are received within suitable recesses or holes 162 formed respectively in the adjacent faces of the bearing extensions of supporting members 144, as shown in Figs. 10 through 12. The springs 152 are of adequate strength to force the outer ends of supporting members 144, and correspondingly the rollers 96 of each pair thereof, equally and oppositely away from each other and into engagement with the innermost cylindrical portions 100 of the rails 98 as best shown in Fig. 11. Such spreading of the outer ends of member 144 and the rollers 96 away from each other serves to center the unit 94 relative to the track comprising rails 98 and the yieldability of the springs 152 permits the rollers 96 at all times to firmly engage the rails as well as to more suitable compensate for any irregularities in the rails or dilferences in spacing between the opposing rail edges 100. It is to be understood howeverthat various types of expansible means the rails, but rather, the rails must be sprung apart slightly to disengage the unit 94 from the rails 98. This is a safety feature to prevent accidental separation. Thus, while in the embodiment shown in Figs. 1 through 8, the rollers 64 are moved toward each other to engage the opposite edges of a so-called mono-rail, in the embodiment in Figs. 9 through 14, the rollers 96 are moved away from each other in each pair respectively to engage the spaced rails 98.

In the event the halves 112 and 114, and particularly 114, are desired to be of metal, it will be understood that appropriate insulation will be installed between the halves 112 and 114 and the current conducting members of the mobile unit.

The electric circuit of the motor 118 illustrated in the embodiment for Figs. 9 through 14 is more simple than the circuit shown for the embodiment shown in Figs. -1 through 8. As shown in Fig. 10, electric leads 164' extend from opposite ends of the motor 118 and the outer ends of such leads, which preferably are flexible, have terminal ends which are connected respectively to one of the supporting members 144 of each pair thereof by insertion in a hole, preferably in the supporting member of each pair which mounts the metallic roller 96. Al though the supporting members 144 are preferably metallic and engage each other, the fact that one wheel 96 of each pair is formed from insulating material, will insure that the metallic wheel of each pair will conduct current to-or from the leads 164 of the motor 118. It will be understood that the opposite wheels of each pair of rollers 96 are metallic and respectively engage different rails of the track. The ties 104 are of insulating material so as to prevent short circuiting of the current between the rails.

While the present invention has primarily been (1%. scribed above as utilizing electric motors, energized by trolley-like conductors, to propel the mobile units 10. and 94, it is to be understood that other forms of power means may be used such as a battery operated electric motor or gasoline motor of suitable size. Under such circumstances, it would not be necessary to use rollers 64 and 96 made of insulating material but nevertheless the construction of the rollers, the supporting members 44 and 144, and springs '79 and 152 could be utilized to attach the mobile unit to the tracks by the same principles as described above relative to the use of the electric motors 61D and 118. Further, under such circumstances, the flanged track 12 and rails 98, and the grooved rollers 64 and 96 would function primarily in a mechanical capacity alone rather than additionally in an additional electrical conducting capacity. Hence, the track 12 could have the conducting wires 18 eliminated therefrom but would still be provided with suitable curved edged flanges extending in opposite directions and resembling the T-shaped cross-sectional formation of the track 12 illustrated in Figs. 4, 5 and 7. The rails 98 would need no change.

From the foregoing, it will be seen that the present invention provides several embodiments of a simple and useful type of mobile unit and track system for supporting and guiding a mobile unit during the movement of the unit along the track." Any convenient source of power means such as an electric motor may be utilized to drive one or more of such mobile units. The mono-rail type of track and other spaced rail type shown herein may be either permanently or temporarily attached to a suitable supporting surface such as a wall, ceiling, floor or the like, including display windows, store exteriors, etc., for purposes of supporting and having mobile units of any desired configuration and ornamentation moved along said track for either utilitarian, decorative, advertising, or toy purposes. The unit or units are capable of being moved at considerably higher speeds relative to the track than is now possible with conventional toy trains, for example, which merely rest upon track rails by gravity, and the units will remain connected to the track and move therealong regardless of whether the track is connected to a floor, a vertical surface such as a wall of a room, or extends along a ceiling, whereby the mobile units depend from the track while moving along such areas of track. No accidental separation of the mobile units from the track is possible even while moving at such relatively high speeds or in depending position, yet when it is desired to disconnect the units from or connect them to such track, such operations may be achieved readily. Further, providing each unit with at least four wheels or rollers, all of which are driven, provides ample frictional engagement to propel the mobile unit along a track, regardless of Whether the track is horizontal, vertical, spirally twisted curved or otherwise.

Where the unit is intended to be operated by electric power, several specific embodiments of simple and efficient electrical circuit systems and members are illustrated and described. Variations are possible therein Without departure from the invention. Further, both the track and mobile units, as illustrated herein, are capable of being manufactured at reasonable costs due to their simplicity and the utilization of pluralities of similar parts, the entire structure also being rugged and capable of long life.

While the invention has been shown and illustrated in its several preferred embodiments, and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as claimed.

I claim:

1. Elongated track means comprising a pair of sub.-

s-tantially parallel and-transversely spaced elongated rail.

members, and means connected to said rail members to support the same for engagement by the wheels of a mobile unit and arranged to be connected to a supporting surface, in combination with a mobile unit to travel upon and be supported by said track means, said unit comprising a base member, two pairs of opposed rollers having peripheral grooves therein arranged to engage the elongated rail members of said track means and receive said rails within the grooves thereof to support said unit from said rails, pairs of roller supporting means interconnected to said base member for pivotal movement in opposite directions transverse to the longitudinal axis of said unit and respectively supporting said pairs of opposed roll rs for independent movement relative to said base member and each other resilient means interengaging each of said pairs of roller supporting means and simultaneously urging said supporting means of each pair substantially equally and oppositely in directions to position the rollers supported thereby respectively into supporting engagement with the rail members of said track means and maintain said mobile unit substantially cent'rally of said track means, said resilient means permitting said rollers to adjust automatically to variations in said track means to maintain said mobile unit centrally thereof, and power means supported by said base .member and interconnected to said rollers to drive the same in rotary directions to propel said mobile unit in a desired direction along said track means.

2. The track and mobile unit combination set forth in claim 1 further characterized by said pairs of roller supporting means each comprising a pair of elongated supporting members provided with bearings and shafts respectively rotatably supported by said bearings thereof, the rollers of each pair respectively being connected to and driven by said shafts.

3. The track and mobile unit combination set forth in claim 2 further characterized by said pairs of elongated supporting members and shafts being spaced longitudinally of said mobile member, and means movably connecting each supporting member of said pairs thereof to said base member substantially along an axis extending longitudinally of said base member.

4. The track and mobile unit combination set forth in claim 3 further characterized by said means for movably connecting said supporting members to said base member comprising bearing and shaft means ertending along a common axis substantially longitudinally and centrally of said base member and parallel to said track means.

5. The track and mobile unit combination set forth in claim 2 further characterized by said resilient means comprising spring means engaging said elongated supporting members of each pair and substantially equally urging said members in opposite directions to effect engagement between the rollers of each pair respectively with the rail members of the track means therefor.

6. The track and mobile unit combination set forth in claim 2 further characterized by said elongated supporting members and shafts therein extending transversely from said base member in normal use and the rollers of each pair thereof being connected respectively to the outer ends of said shafts carried by said supporting members and extending transversely thereto.

7. The track and mobile unit combination set forth in claim 6 further including worm gears connected respectively to the inner ends of said shafts, and a driving worm for each pair of shafts commonly engaging said worm gears and operable to rotate the shafts of each pair of supporting members and the rollers thereon in opposite rotary directions.

8. Elongated track means comprising a pair of substantially parallel and transversely spaced elongated rail members and means connected to said rail members and extending therebetween to support the same for engagement by the wheels of a mobile unit and arranged to be connected to a supporting surface, in combination with a mobile unit to travel upon and be supported by said track means, said unit comprising a base member, two pairs of opposed rollers having peripheral grooves therein arranged to engage the elongated rail members of said track means, pairs of supporting members each hav ing one end interconnected to said base member for movement of the other ends toward and away from the longitudinal axis of said unit and said pairs being spaced from each other in the direction of said axis, said pairs of supporting members adjacent said other ends thereof respectively supporting said pairs of opposed rollers for independent movement of the rollers of each pair relative to said base member and each other in opposite directions, resilient means yieldably interengaging each of said pairs of roller supporting members and simultaneously urging said members of each pair substantially equally and oppositely toward each other in directions to position the rollers supported thereby respectively into supporting engagement with the rail members of said track means and maintain said mobile unit substantially centrally of said track means, and power means supported by said base member and interconnected to said rollers to drive the same in rotary directions to propel said mobile unit in a desired direction along said track means.

9. The track and mobile unit combination set forth in claim 8 further characterized by said pairs of roller supporting members each having elongated bearings rotatably supporting shafts, said members being pivotally supported adjacent one end of each and the shafts pr0- jecting beyond the other ends thereof, the rollers of each pair respectively being connected to the projecting ends of said shafts and driven thereby, and said resilient means comprising springs engaging said otherends of said elongated bearings of said supporting members.

10. The track and mobile unit combination set forth in claim 9 further characterized by said means for movably connecting said supporting members to said base member comprising bearing and shaft means extending along a common axis substantially longitudinally and centrally of said base member.

11. The track and mobile unit combination set forth in claim 10 further including gear means connected respectively to the opposite ends of said shafts, and a driving gear for each pair of shafts engaging said gear means and operable to rotate the shafts of each pair of supporting members and the rollers thereon in opposite rotary directions.

12. Elongated track means comprising a pair of substantially parallel and transversely spaced elongated rail members, and means connected to said rail members to provide a clear space therebetween and support the same for engagement by the Wheels of a mobile unit, and means operable to connect said rails to a supporting surface, in combination With a mobile unit to travel upon and be supported by said track means, said unit comprising a base member, two pairs of opposed rollers arranged to be positioned within the clear space between said rails and having peripheral grooves therein arranged to engage the elongated rail members of said track means, pairs of roller supporting members movably interconnected adjacent one end to said base member and respectively supporting said pairs of opposed rollers adjacent the other ends thereof for independent movement relative to said base member and each other in opposite directions, resilient means yieldably interengaging each of said pairs of roller supporting members adjacent said other ends thereof and simultaneously urging said other ends and rollers apart substantially equally in directions to force the rollers respectively into supporting engagement with said spaced rail members of said track means and thereby maintain said mobile unit substansupported by said base member and interconnected to 13 said rollers to drive the same in rotary directions to propel said mobile unit in a desired direction along said track means.

13. The track and mobile unit combination set forth in claim 12 further characterized by said pairs of roller supporting members each having elongated bearings, shafts respectively supported therein and projecting beyond said bearings and the rollers of each pair respectively connected to the projecting ends of said shafts and driven thereby.

14. The track and mobile unit combination set forth in claim 13 further including gear means connected respectively to the other ends of said shafts, and a driving gear for each pair of shafts engaging said gear means and operable to rotate the shafts of each pair of supporting members and the rollers thereon in opposite directions, said power means also comprising a motor having a shaft projecting from opposite ends thereof and a driving gear being connected to each projecting end of said shaft.

15. The track and mobile unit combination set forth in claim 12 further characterized by said base member having struts extending longitudinally thereof and said 14 resilient means comprising a U-shaped spring extending over each strut respectively for each pair of supporting member and the ends of said springs respectively engaging said supporting members adjacent said other ends thereof.

References Cited in the file of this patent UNITED STATES PATENTS 706,139 Werner Aug. 5, 1902 911,221 Ellsworth Feb. 2, 1909 1,412,829 Bennington Apr. 18, 1922 1,454,806 Wright May 8, 1923 2,132,187 Rand Oct. 4, 1938 2,228,034 Nelles Jan. 7, 1941 2,229,015 King Jan. 14, 1941 2,276,645 Bonanno Mar. 17, 1942 2,394,168 Goga Feb. 5, 1946 2,619,553 Kroeckel Nov. 25, 1952 2,645,187 Guadagna July 14, 1953 2,685,844 Short et a1 Aug, 10, 1954 FOREIGN PATENTS 443 Great Britain of Jan. 7, 1903 

